Go語言結構
Go數組允許定義類型的變量，可容納同類的多個數據項，但結構在Go編程，它允許結合不同種類的數據項，可使用其他用戶定義的數據類型。
結構是用來代表一個記錄，假設要跟蹤圖書館的圖書。可能要跟蹤有關每本書以下屬性：
-
Title(書名)
-
Author(作者)
-
Subject(科目)
-
Book ID(編號)
定義結構
定義一個結構，必須使用type和struct語句。該結構語句定義了一個新的數據類型，項目不止一個成員。類型語句是結構在我們的案例類型綁定的名稱。該結構語句的格式是這樣的：
type struct_variable_type struct {
member definition;
member definition;
...
member definition;
}
一旦結構類型定義，它可以被用來聲明使用以下語法類型的變量。
variable_name := structure_variable_type {value1, value2...valuen}
訪問結構成員
要訪問結構的成員，我們使用成員訪問運算符(.)。成員訪問運算符是編碼作為結構變量名，並且我們希望訪問結構部件之間的周期。可使用struct關鍵字來定義結構類型的變量。以下為例子來解釋結構的用法：
package main
import "fmt"
type Books struct {
title string
author string
subject string
book_id int
}
func main() {
var Book1 Books /* Declare Book1 of type Book */
var Book2 Books /* Declare Book2 of type Book */
/* book 1 specification */
Book1.title = "Go Programming"
Book1.author = "Mahesh Kumar"
Book1.subject = "Go Programming Tutorial"
Book1.book_id = 6495407
/* book 2 specification */
Book2.title = "Telecom Billing"
Book2.author = "Zara Ali"
Book2.subject = "Telecom Billing Tutorial"
Book2.book_id = 6495700
/* print Book1 info */
fmt.printf( "Book 1 title : %s\n", Book1.title)
fmt.printf( "Book 1 author : %s\n", Book1.author)
fmt.printf( "Book 1 subject : %s\n", Book1.subject)
fmt.printf( "Book 1 book_id : %d\n", Book1.book_id)
/* print Book2 info */
fmt.printf( "Book 2 title : %s\n", Book2.title)
fmt.printf( "Book 2 author : %s\n", Book2.author)
fmt.printf( "Book 2 subject : %s\n", Book2.subject)
fmt.printf( "Book 2 book_id : %d\n", Book2.book_id)
}
當上述代碼被編譯和執行時，它產生了以下結果：
Book 1 title : Go Programming Book 1 author : Mahesh Kumar Book 1 subject : Go Programming Tutorial Book 1 book_id : 6495407 Book 2 title : Telecom Billing Book 2 author : Zara Ali Book 2 subject : Telecom Billing Tutorial Book 2 book_id : 6495700
結構作為函數參數
可以傳遞一個結構作為函數的參數，非常類似傳遞任何其他變量或指針的方式。您可以訪問，就象在上麵的例子已經訪問的方式類似的結構變量：
package main
import "fmt"
type Books struct {
title string
author string
subject string
book_id int
}
func main() {
var Book1 Books /* Declare Book1 of type Book */
var Book2 Books /* Declare Book2 of type Book */
/* book 1 specification */
Book1.title = "Go Programming"
Book1.author = "Mahesh Kumar"
Book1.subject = "Go Programming Tutorial"
Book1.book_id = 6495407
/* book 2 specification */
Book2.title = "Telecom Billing"
Book2.author = "Zara Ali"
Book2.subject = "Telecom Billing Tutorial"
Book2.book_id = 6495700
/* print Book1 info */
printBook(Book1)
/* print Book2 info */
printBook(Book2)
}
func printBook( book Books )
{
fmt.printf( "Book title : %s\n", book.title);
fmt.printf( "Book author : %s\n", book.author);
fmt.printf( "Book subject : %s\n", book.subject);
fmt.printf( "Book book_id : %d\n", book.book_id);
}
當上述代碼被編譯和執行時，它產生了以下結果：
Book title : Go Programming Book author : Mahesh Kumar Book subject : Go Programming Tutorial Book book_id : 6495407 Book title : Telecom Billing Book author : Zara Ali Book subject : Telecom Billing Tutorial Book book_id : 6495700
指針結構
可以非常相似定義指針結構的方式，為您定義指向任何其他變量，如下所示：
var struct_pointer *Books
現在，你可以存儲結構變量的地址在上麵定義的指針變量。為了找到一個結構變量的地址，使用&運算符結構在名字前，如下所示：
struct_pointer = &Book1;
要訪問結構的使用指針成員的結構，您必須使用“.”運算符，如下：
struct_pointer.title;
讓我們使用結構指針重新寫上麵的例子，希望這可以幫助您理解概念：
package main
import "fmt"
type Books struct {
title string
author string
subject string
book_id int
}
func main() {
var Book1 Books /* Declare Book1 of type Book */
var Book2 Books /* Declare Book2 of type Book */
/* book 1 specification */
Book1.title = "Go Programming"
Book1.author = "Mahesh Kumar"
Book1.subject = "Go Programming Tutorial"
Book1.book_id = 6495407
/* book 2 specification */
Book2.title = "Telecom Billing"
Book2.author = "Zara Ali"
Book2.subject = "Telecom Billing Tutorial"
Book2.book_id = 6495700
/* print Book1 info */
printBook(&Book1)
/* print Book2 info */
printBook(&Book2)
}
func printBook( book *Books )
{
fmt.printf( "Book title : %s\n", book.title);
fmt.printf( "Book author : %s\n", book.author);
fmt.printf( "Book subject : %s\n", book.subject);
fmt.printf( "Book book_id : %d\n", book.book_id);
}
當上述代碼被編譯和執行時，它產生了以下結果：
Book title : Go Programming Book author : Mahesh Kumar Book subject : Go Programming Tutorial Book book_id : 6495407 Book title : Telecom Billing Book author : Zara Ali Book subject : Telecom Billing Tutorial Book book_id : 6495700
